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A One-pot Approach to Ethyl 1,4,5-Triaryl-lH-pyrazole-3- carboxylates via an Improved claisen condensation- Knorr Reaction Sequence

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Chinese Journal of Chemistry 2013年第12期31卷 1526-1538页

作者： Jiaojiao Zhai Chunhui Gu Jianan Jiang Shunli Zhang Daohua Liao Lei Wang Dunru Zhu Yafei Ji School of Pharmacy East China University of Science and Technology Shanghai 200237 China State Key Laboratory of Materials-oriented Chemical Engineering College of Chemistry and Chemical Engineering Nanjing University of Technology Nanjing Jiangsu 210009 China

A one-pot approach to ethyl 1,4,5-triaryl-lH-pyrazole-3-carboxylates has been developed in moderate to high yields. The tert-BuOLi-mediated claisen condensation of 1,2-diarylethanones and ethyl oxalyl chloride efficiently provided the enolized lithium salts of ethyl 2,4-dioxo-3,4-diarylbutanoates, which in situ reacted with arylhydrazine hydrochlorides via a hydrochloric acid-promoted Knorr reaction to produce the exquisite triarylpyrazole-3- carboxylates. The procedure promises a convenient access to this highly crowded framework for drug discovery.

关键词： one-pot approach 2,4-dioxo-3,4-diarylbutanoates claisen condensation Knorr reaction triarylpyrazole-3-carboxylates

Enhancing the activity and succinyl-CoA specificity of 3-ketoacyl-CoA thiolase Tfu_0875 through rational binding pocket engineering

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Synthetic and Systems Biotechnology 2024年第3期9卷 558-568页

作者： Lixia Liu Shuang Liu Xiangyang Hu Shenghu Zhou Yu Deng National Engineering Research Center of Cereal Fermentation and Food Biomanufacturing Jiangnan University1800 Lihu RoadWuxiJiangsu214122China Jiangsu Provincial Research Center for Bioactive Product Processing Technology Jiangnan University1800 Lihu RoadWuxiJiangsu214122China

The 3-ketoacyl-CoA thiolase is the rate-limiting enzyme for linear dicarboxylic acids ***,the promiscuous substrate specificity and suboptimal catalytic performance have restricted its *** we present both biochemical and structural analyses of a high-efficiency 3-ketoacyl-CoA thiolase Tfu_***,Tfu_0875 displayed heightened activity and substrate specificity for succinyl-CoA,a key precursor in adipic acid *** enhance its performance,a deep learning approach(DLKcat)was employed to identify effective mutants,and a computational strategy,known as the greedy accumulated strategy for protein engineering(GRAPE),was used to accumulate these effective *** the mutants,Tfu_0875N249W/L163H/E217L exhibited the highest specific activity(320%of wild-type Tfu_0875),the greatest catalytic efficiency(kcat/KM=1.00 min-1mM-1),the highest succinyl-CoA specificity(KM=0.59 mM,28.1%of Tfu_0875)and dramatically reduced substrate binding energy(-30.25 kcal mol^(-1)v.s.-15.94 kcal mol^(-1)).A structural comparison between Tfu_0875N249W/L163H/E217L and the wild type Tfu_0875 revealed that the increased interaction between the enzyme and succinyl-CoA was the primary reason for the enhanced enzyme *** interaction facilitated rapid substrate anchoring and ***,a reduced binding pocket volume improved substrate specificity by enhancing the complementarity between the binding pocket and the substrate in stereo ***,our rationally designed mutant,Tfu_0875N249W/L163H/E217L,increased the adipic acid titer by 1.35-fold compared to the wild type Tfu_0875 in shake *** demonstrated enzymatic methods provide a promising enzyme variant for the adipic acid *** above effective substrate binding pocket engineering strategy can be beneficial for the production of other industrially competitive biobased chemicals when be applied to other thiolases.

关键词： Adipic acid 3-Ketoacyl-CoA thiolase claisen condensation Deep learning GRAPE strategy

An Efficient One-pot Synthesis of Aryl-substituted 1-(Thiazol-2-yl)-1H-pyrazole-3-carboxylates via a Hantzsch Synthesis-Knorr Reaction Sequence

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Chinese Journal of Chemistry 2014年第2期32卷 179-190页

作者： Chunhui Gu Jiaojiao Zhai Jianan Jiang Hongwei Liu Lei Wang Dunru Zhu Yafei Ji School of Pharmacy East China University of Science and TechnologyShanghai 200237China State Key Laboratory of Materials-Oriented Chemical Engineering College of Chemistry and Chemical EngineeringNanjing University of TechnologyNanjingJiangsu 210009China

The treatment ofα-bromoalkyl aryl ketones and 2-(propan-2-ylidene)hydrazine carbothioamide afforded 4-aryl-2-(2-(propan-2-ylidene)hydrazinyl)thiazoles via a Hantzsch-thiazole synthesis,which reacted with 4-aryl-2,4-diketoesters via a sequential Knorr-pyrazole reaction to deliver a variety of aryl-substituted ethyl 1-(thiazol-2-yl)-1Hpyrazole-3-carboxylates in a one-pot fashion with moderate to high *** key intermediates 4-aryl-2,4-diketoesters,existing as its enolic lithium salt,were synthesized in situ by a high-yield tert-BuOLi-mediated claisen condensation of alkylphenones and diethyl *** class of elegant molecule comprises aryl groups on the two different heterocyclic cores,and the configurations of two representative molecules were determined by single crystal X-ray crystallography.

关键词： one-pot synthesis claisen condensation Hantzsch synthesis Knorr reaction 1-(thiazol-2-yl)pyrazole-3-carboxylates

A modified total synthesis of cystothiazole A

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Science China Chemistry 2009年第9期52卷 1345-1352页

作者： YueXia Bai JiLai Bao Jun Ren ZhongWen Wang State Key Laboratory of Elemento-Organic Chemistry Institute of Elemento-Organic Chemistry Nankai University Tianjin 300071 China

A modified total synthesis of cystothiazole A is described. In this synthetic strategy, a one-step transformation of acylated oxazolidinone to β-ketoester has been successfully applied, thus making the synthetic route more efficient. This method may also be potentially applied in synthesis of other related β-substituted-β-methoxyl acrylates (bb-MOAs).

关键词： cystothiazole A β -methoxyl acrylate claisen condensation Aldol total synthesis

Synthesis of furanyl-functionalized β-diketone

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Synthesis of furanyl-functionalized β-diketone